Question

Number of positive integers which have characteristic $2$ when base is $10$, is

• A. $900$
• B. $901$
• C. $180$
• D. $181$

Answer 1

The correct option is A $900$

Let the integers be represented by $N$.
Then $2\le {\log }_{10}N<3$
$\Rightarrow {10}^2\le N<{10}^3$
$\therefore$ Number of such positive integers, $N$ is ${10}^3-{10}^2=900$